1. Field
Apparatuses and methods consistent with exemplary embodiments relate to optical apparatuses including layers having high refractive indices and methods of manufacturing the optical apparatuses, and more particularly, to an optical apparatus, such as an image sensor, a light-emitting diode (LED), or an organic light-emitting diode (OLED), including an optical functional layer having a high refractive index and a method of manufacturing the optical apparatus.
2. Description of the Related Art
Color display devices or color image sensors usually display an image of various colors or detect a color of incident light by using a color filter. An RGB color filter method, in which, for example, a green filter is arranged at two pixels from among four pixels and a blue filter and a red filter are arranged in the other two pixels, is widely employed by currently used color display devices or color image sensors. In addition to the RGB color filter method, a CYGM color filter method may be employed in which color filters of cyan, yellow, green, and magenta, which are complementary colors, are respectively arranged at four pixels.
However, a color filter may have low light use efficiency because the color filter absorbs light of colors other than a color corresponding to the color filter. For example, when an RGB color filter is in use, only ⅓ of the incident light is transmitted and the other portion, that is, ⅔, of the incident light is absorbed. Accordingly, the light use efficiency may be about 33%. Accordingly, for a color display device or color image sensor, most light loss occurs in the color filter.
Recently, to improve the light use efficiency of color display devices or color image sensors, a color separation layer is used instead of the color filter. The color separation layer may separate the color of an incident light by using the diffraction or refraction characteristics of light that vary according to a wavelength of the light. The colors separated by the color separation layer may be respectively provided to pixels of an image sensor, which correspond to the colors. It is known that color separation characteristics are improved as a refractive index of the color separation layer increases.